MAGNETIC SENSOR DEVICE HAVING AN ENCLOSURE WITH STEP PORTIONS AND GROOVES CONTINUOUS WITH THE STEP PORTIONS AND METHOD OF MANUFACTURE THEREOF
A magnetic sensor device including: a board mounted with a magnetoresistive effect element, a magnet to form a bias magnetic field for the magnetoresistive effect element, an enclosure having an opening on a side of a conveyance path where a to-be-detected object is conveyed, also including a housing portion to house the magnet and the board, and a cover to cover a surface on a side of the opening of the housing portion. The enclosure includes step portions on which the board is supported such that the board lies across the opening and extends parallel to the conveyance path, and grooves, continuous with the step portions, extending from the opening to an outer surface of the enclosure on a side of the conveyance direction.
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This application is a Continuation of U.S. application Ser. No. 15/313,398, filed Nov. 22, 2016, which is a national phase application of International Application No. PCT/JP2015/070035, filed Jul. 13, 2015 and claims priority to Japanese Patent Application 2014-151844, filed Jul. 25, 2014, the entire contents of which are incorporated herein by reference.
TECHNICAL FIELDThe present disclosure relates to a magnetic sensor device that detects a magnetic pattern printed on paper currency and the like and relates to a manufacturing method thereof.
BACKGROUND ARTMagnetic sensor devices that detect magnetic patterns printed on paper currency are used for determining the authenticity of paper currency and the like. A magnetic sensor device includes a magnetoresistive effect element, a magnet to apply a bias magnetic field for the magnetoresistive effect element, an enclosure to support the magnetoresistive effect element and the magnet, and a cover to protect the magnetoresistive effect element. The magnet and the magnetoresistive effect element are fixed to the enclosure of the magnetic sensor device and are covered by the cover.
Patent Literature 1 discloses a metal cover that is formed through a simple process and discloses a magnetic sensor structure in which the metal cover and a body can be fixed easily so as not to come apart from each other. In the magnetic sensor of Patent Literature 1, the metal cover is fixed to the insulation casing by coupling a metal-cover-side coupling part provided on the metal cover together with an insulation-casing-side coupling part provided on the insulation casing.
In the magnetic sensor in Patent Literature 2 claw-portion engaging grooves are provided in the side surfaces of the casing, and cover fixing claw portions to be engaged with the claw-portion engaging grooves are provided for the cover. The claw-portion engaging grooves are each provided with protrusions that protrude into the claw-portion engaging groove, and notches are provided for the cover. At the time of sliding the cover to a predetermined location with respect to the casing, the notches are engaged with the protrusions to position and fix both the casing and the cover.
CITATION LIST Patent LiteraturePatent Literature 1: Unexamined Japanese Patent Application Kokai Publication No. H11-66517
Patent Literature 2: Unexamined Japanese Patent Application Kokai Publication No. 2001-59860
SUMMARY OF INVENTION Technical ProblemThe magnetic sensors in Patent Literature 1 and Patent Literature 2 each have a structure in which an engaging piece provided on the metal cover is used to fix the metal cover to the insulation casing for the fixing of the body of the magnetic sensor and the metal cover together. These magnetic sensors are intended for the specific purpose of fixing a metal cover to a casing without a sealing resin for fixing, which was once necessary. The magnetic sensors in Patent Literature 1 and Patent Literature 2 do not seal a magnetoresistive effect element.
In the case of fixedly attaching a metal cover and a board mounted with a magnetoresistive effect element to an enclosure, that is, fixedly attaching two independent articles to the enclosure, there was an issue of having to divide the fixing job into two tasks because, for example, the enclosure and the board first had to be fixedly attached together before the metal cover could be fixed to the enclosure fixedly attached with the board.
The present disclosure has been made in view of the foregoing, and an object of the present disclosure is to fixedly attach at the same time to an enclosure of a magnetic sensor device, a magnetoresistive effect element-mounted board and a cover for protecting the magnetoresistive effect element.
Solution to ProblemIn order to achieve the aforementioned object, a magnetic sensor device of the present disclosure includes a board mounted with a magnetoresistive effect element, a magnet to form a bias magnetic field for the magnetoresistive effect element, an enclosure having an opening on a side of a conveyance path where a to-be-detected object containing a magnetic component is conveyed, and housing the magnet and the board with the magnetoresistive effect element being disposed on the side of the conveyance path, and a cover to cover a plane on a side of the opening of the enclosure. The enclosure includes step portions on which the board is supported in such a manner that the board lies across the opening on the side of the conveyance path and extends along a conveyance direction of the to-be-detected object, and includes grooves, continuous with the step portions, extending from the opening to an outer surface of the enclosure on a side of the conveyance direction.
A magnetic sensor device manufacturing method of the present disclosure includes an adhesive application step for applying an adhesive onto step portions and grooves of an enclosure, wherein (i) the enclosure has an opening on a side of a conveyance path where a to-be-detected object containing a magnetic component is conveyed and the enclosure houses (ia) a board mounted with a magnetoresistive effect element disposed on the side of the conveyance path and (ib) a magnet to form a bias magnetic field for the magnetoresistive effect element, (ii) the step portions support a board in such a manner that the board lies across the opening on the side of the conveyance path and extends along a conveyance direction of the to-be-detected object, and (iii) the grooves, continuous with the step portions, extend from the opening to an outer surface of the enclosure on a side of the conveyance direction, a board placement step for placing the board on the step portions such that the board lies across the opening and extends along the conveyance direction of the to-be-detected object, a cover placement step for placing a cover on a surface of the opening of the enclosure so as to cover the surface of the opening side of the enclosure, and an adhesive curing step for curing the adhesive after the board placement step and the cover placement step.
Advantageous Effects of InventionThe magnetic sensor device and the manufacturing method thereof enable the cover for protecting the magnetoresistive effect element and the board mounted with the magnetoresistive effect element to be fixedly attached to the enclosure at the same time because (i) the step portions formed at the opening to support the board that is laid along the conveyance direction of the to-be-detected object, and (ii) the grooves, continuous with the step portions, extending from the opening to the outer surface of the enclosure on a side of the conveyance direction are provided.
Hereinafter, the embodiments of the present disclosure are described in detail with reference to the drawings. In the drawings, the same or corresponding portions are marked with the same reference signs.
Embodiment 1To fixedly attach the board 2 and the cover 5 to the enclosure 4, the adhesive 11a applied and spread on the step portions 4b, the opening outer edges 4d, and grooves 4c of the enclosure 4 to which the board 2 is attached, causes the board 2 to fixedly attach to the step portions 4b of the enclosure 4. Next, the cover 5 fixedly attaches to the opening outer edges 4d of the enclosure 4. The thickness of the adhesive 11 is greater than the space between the cover 5 and the opening outer edges 4d of the enclosure 4, but the cover 5 and the grooves 4c of the enclosure 4 are fixedly attached together. The magnetic sensor device in
The magnet 3 forms a magnetic field in a space which the conveyance path crosses. The magnetic sensor device detects changes in the magnetic field caused by the magnetic component of the to-be-detected object 6 and detects a magnetic pattern of the to-be-detected object 6. The magnetoresistive effect element 1 is disposed on the board 2 so as to extend in a direction orthogonal to a paper surface in
Although there is no single set way to dispose the magnetic poles of the magnet 3, magnetic lines of force that extend from one of the poles of the magnet 3 interlink with the conveyance path along which the to-be-detected object 6 is conveyed and then enter the other magnetic pole. The cover 5 is non-magnetic, thereby enabling the magnetic lines of force of the magnet 3 to unaffectedly pass through the cover 5. The magnetoresistive effect element 1 is disposed within the magnetic field of the magnet 3 and the magnet 3 forms a bias magnetic field for the magnetoresistive effect element 1.
The enclosure 4 has a housing portion 4h to house the board 2 and the magnet 3. The housing portion 4h has an opening 4a on the side of the conveyance path. The enclosure 4 has the opening 4a on the side of the conveyance path, and the magnet 3 is inserted and housed in the housing portion 4h via the opening 4a. The housing portion 4h includes step portions 4b where the board 2 is supported at opposite sides thereof on the step portions 4b in such a manner that the board 2 lies on the side of the opening 4a facing the conveyance path. In the housing portion 4h illustrated in
The opening outer edges 4d of the enclosure 4 that come in contact with the cover 5 on a side of the conveyance path slant away from the conveyance path, as the opening outer edges 4d approach the outer surface (side walls 4g) in the conveyance direction from the opening 4a. The opening outer edges 4d slanted in this manner are continuous with the side walls 4g extending in the main scanning direction of the enclosure 4. The grooves 4c of the enclosure 4 likewise are slanted away from the conveyance path, as the grooves 4c approach the outer surface in the conveyance direction from the opening 4a. The grooves 4c slanted in this manner are connected to the side walls 4g extending in the main scanning direction of the enclosure 4. In other words, the opening outer edges 4d and the grooves 4c reside between the opening 4a and each of the side walls 4g and extend in the main scanning direction. Specifically, the opening outer edges 4d and the grooves 4c may be regarded as being alternatingly arranged along the main scanning direction. Also, the grooves 4c may be regarded as indentations along the conveyance direction 7 formed on the opening outer edges 4d formed along the main scanning direction. Further, the opening outer edges 4d may be regarded as being formed along the main scanning direction and may also be regarded as being protrusions formed along the conveyance direction 7. The grooves 4c are formed between these protrusions. The cover 5 is formed so as to align with the opening outer edges 4d of the enclosure 4. The board 2 and the cover 5 are fixed to the enclosure with the adhesive 11. The adhesive 11 is also interposed between the cover 5 and the grooves 4c.
Bringing the magnet 3 into contact with the board 2 mitigates warpage or bending of the board 2. Also, the bringing of the magnet 3 into contact with the board 2 enables the magnet 3 to function as a heat sink for dissipating heat generated from the magnetoresistive effect element 1, circuit elements of the board 3, and the like. The reason is that the fixing of the board 2 to the step portions 4b so as to bridge the step portions 4b that are facing the conveyance direction 7 easily widens the contact area between the board 2 and the magnet 3. This also inhibits the excess portion of the adhesive 11 that is thrusted from the step portions 4b from flowing into the magnet 3 side. Accordingly, the length of the magnet 3 in the conveyance direction 7 can be increased, thereby enabling even easier widening of the contact area between the board 2 and the magnet 3. When the magnet 3 is made to function as a heat sink, a heat dissipation member having high heat conductivity such as a bus bar may be situated thermally-adjacent to the magnet 3, so that heat from the magnet 3 dissipates to outside of the enclosure 4. To further increase the conductivity of heat from the board 2 to the magnet 3, a heat conducting member such as a heat-conductive sheet or a heat-conductive gel may be sandwiched between the board 2 and the magnet 3.
On the magnetic sensor device illustrated in
In the step illustrated in
As described above, the cover 5 and the board 2 mounted with the magnetoresistive effect element 1 in the magnetic sensor device of Embodiment 2 can be fixed more tightly together compared to that of Embodiment 1. Since the affixing of the double-sided adhesive 21 to the cover 5 is performed before the adhesive 11 is applied to the step portions 4b, the board 2-and-cover 5 attachment step is unaffected.
Embodiment 3In the step illustrated in
As described above, the magnetic sensor device in Embodiment 3 of the present disclosure enables the cover 5 to be electrically connected to the ground.
The foregoing describes some example embodiments for explanatory purposes. Although the foregoing discussion has presented specific embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the broader spirit and scope of the invention. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. This detailed description, therefore, is not to be taken in a limiting sense, and the scope of the invention is defined only by the included claims, along with the full range of equivalents to which such claims are entitled.
This application claims the benefit of Japanese Patent Application No. 2014-151844, filed on Jul. 25, 2014, the entire disclosure of which is incorporated herein by reference.
REFERENCE SIGNS LIST
- 1 Magnetoresistive effect element
- 2 Board
- 2a Dam board
- 3 Magnet
- 4 Enclosure
- 4a Opening
- 4b Step portion
- 4c Groove
- 4d Opening outer edge
- 4g Side wall
- 4h Housing portion
- 5 Cover
- 5a Terminal hole
- 6 To-be-detected object
- 7 Conveyance direction
- 11 Adhesive
- 21 Double-sided adhesive tape
- 31 Screw
Claims
1: A magnetic sensor device, comprising:
- a board mounted with a magnetoresistive effect element;
- a magnet to form a bias magnetic field for the magnetoresistive effect element;
- an enclosure having an opening on a side of a conveyance path where a to-be-detected object containing a magnetic component is conveyed, and housing the magnet and the board, the magnetoresistive effect element being disposed on the side of the conveyance path; and
- a cover to cover a plane on a side of the opening of the enclosure,
- wherein the enclosure has step portions on which the board is supported in such a manner that the board lies across the opening on the side of the conveyance path and extends along a conveyance direction of the to-be-detected object, and
- wherein the enclosure has a plurality of grooves continuous with the step portions, the plurality of grooves extending from the opening to an outer surface of the enclosure along the conveyance direction.
2: The magnetic sensor device according to claim 1, wherein a surface of the enclosure contacting the cover on the side of the conveyance path slants away from the conveyance path, as the surface of the enclosure approaches the outer surface along the conveyance direction.
3: The magnetic sensor device according to claim 2, wherein a bottom surface of the grooves slants away from the conveyance path, as the bottom surface approaches the outer surface of the enclosure along the conveyance direction from the step portions.
4: The magnetic sensor device according to claim 1, wherein the board and the cover are fixed to the enclosure with an adhesive.
5: The magnetic sensor device according to claim 4, wherein
- the cover is fixed to the enclosure on opening outer edges formed on the enclosure along a direction orthogonal to the conveyance direction, and
- the grooves are indentations along the conveyance direction formed on the opening outer edges of the enclosure.
6: The magnetic sensor device according to claim 4, wherein the adhesive is interposed between the cover and the grooves.
7: The magnetic sensor device according to claim 4, wherein the adhesive is interposed between the cover and each of the grooves and step portions, and
- wherein the adhesive of the grooves and the step portions is continuous.
8: The magnetic sensor device according to claim 1, wherein the plurality of grooves are spaced apart from each other in a direction orthogonal to the conveyance direction of the to-be-detected object.
Type: Application
Filed: Jul 3, 2018
Publication Date: Nov 1, 2018
Applicant: Mitsubishi Electric Corporation (Chiyoda-ku)
Inventors: Masaaki OKADA (Chiyoda-ku), Hideki MATSUI (Chiyoda-ku), Tomokazu OGOMI (Chiyoda-ku), Sadaaki YOSHIOKA (Chiyoda-ku)
Application Number: 16/026,143